Various therapeutic and diagnostic medical procedures involve accessing a vein or artery through a percutaneous tissue track. Femoral arteries are commonly accessed during various procedures, such as angiograms, angioplasties, catheterization and peripheral artery angioplasty. Accessing the blood vessel typically includes insertion of a relatively large diameter introducer sheath along the percutaneous tissue track and into an access opening in the blood vessel. Medical instruments, including guidewires and various catheters, are then introduced into the patient""s vascular system through the introducer sheath.
At the conclusion of the medical procedure, the introducer sheath is removed leaving a relatively large access opening in the vessel wall which must be closed to stop bleeding. This has been traditionally accomplished through the use of digital pressure at the puncture site. This, however, requires that direct pressure be applied for an extended period of time, such as 45 minutes to an hour, to effectively stop bleeding from the access opening. Mechanical substitutes for finger pressure have been used, but can be uncomfortable for the patient. Using digital pressure to stop bleeding is not only expensive from the standpoint of the time of the trained medical person applying the pressure, it is also quite physically difficult to maintain a constant pressure at the puncture site for such an extended period. In addition, applying direct pressure to the puncture site causes the vessel being accessed to be blocked which can create its own problems, such as ischemia.
An early alternative to direct pressure to stop bleeding from an access opening in a blood vessel was the use of biodegradable collagen plugs. These plugs are either applied directly on top of the puncture site in the vessel wall, or are secured to the wall with a suture and polymer anchor. In the latter device, the polymer anchor is placed within the artery, against the inner wall of the artery. While such a device worked, it is not desirable to leave a foreign object within the blood vessel.
In lieu of applying direct pressure to the puncture site, hemostasis materials have been used to halt blood flow from the blood vessel access opening. These materials are typically positioned along the percutaneous tissue track using a balloon catheter, the balloon being situated at the distal end of the catheter within the blood vessel. When the balloon is inflated, it effectively seals the opening in the blood vessel to permit the hemostatic material to be properly positioned at the access opening in the blood vessel without being introduced into the vessel. After a period of time, the balloon is deflated and the balloon catheter is withdrawn from the blood vessel and tissue track. These devices require a very small balloon and can be expensive.
The present invention is directed to a percutaneous tissue track closure assembly and a method for sealing the percutaneous tissue track using a semipermeable barrier at the end of the tissue track and hemostatic flowable material within the tissue track so that blood or blood components passing through the semipermeable barrier interact with the hemostatic material to effectively seal the tissue track. The hemostatic material preferably includes both material which swells upon contact with blood or other aqueous fluids and material which causes blood to clot. Using the semipermeable barrier prevents passage of the hemostatic flowable material through the blood vessel access opening and into the blood vessel, while permitting a relatively controlled amount of blood to flow into the percutaneous tissue track to interact with the hemostatic flowable material. One aspect of the invention relates to a method for sealing the percutaneous tissue track. A semipermeable barrier is established at the distal end of the tissue track at the blood vessel puncture site. Hemostatic material is introduced into the tissue track. The semipermeable barrier permits blood, or at least one blood component, to pass from the blood vessel into the tissue track to interact with the hemostatic material and effectively seal the tissue track. The semipermeable barrier prevents the hemostatic material from passing through the access opening and into the blood vessel.
A percutaneous tissue track closure assembly includes broadly a barrier assembly, a flowable material assembly and a delivery tube alignment device. The barrier assembly includes an elongate barrier carrier, typically a tube, having a distal end. The barrier is mounted to the distal end of the barrier carrier. In a preferred embodiment the semipermeable barrier permits blood or blood components to pass through the barrier, but prevents the passage of the hemostatic flowable material through the barrier into the vessel. The barrier can be placed in a laterally retracted, undeployed configuration for passage into and out of the blood vessel, and in a laterally expanded, deployed configuration, when in the blood vessel, by a user-operated barrier actuator. The barrier actuator is, in one embodiment, in the form of a thin wire extending from the barrier and through the tubular barrier carrier; the barrier actuator is pushed to place the barrier in the undeployed configuration and pulled to expand the barrier into its laterally expanded, deployed configuration so the barrier can be used to block the access opening in the blood vessel. In another embodiment, the barrier actuator is in the form of two coaxial tubes, the outer one extending from the barrier and acting as barrier carrier, and the inner one bonded to the outer one at the distal end and acting as a barrier actuator. The outer tube is slit in several places, such as four, in the distal area located directly under the barrier. When the inner tube is pulled proximally relative to the outer tube, the sections of the outer tube located between the slits buckle outwardly and extend into arms which force the barrier to expand into a discus-like or mushroom shape.
In a further embodiment, a barrier carrier is in the form at least one barrier carrier tube, and preferably in the form of inner and outer barrier carrrier tubes, having longitudinally-extending weakened regions, the weakened regions typically being slits formed near the distal ends. The weakened regions of the inner barrier carrier tube are circumferentially offset from the weakened regions of the outer barrier carrier tube. A barrier actuator, typically in the form of a pull wire or tube, is used to pull on the distal ends of both inner and outer barrier carrier tubes causing the inner and outer barrier carrier tubes to buckle at the weakened regions thus causing the arms defined between the weakened regions to be deflected outwardly creating gaps therebetween. The laterally extending arms of the inner barrier carrier tube extend between the gaps created between the arms of the outer barrier carrier tube. The arms create fluid-flow-permitting gaps therebetween. It has been found by properly sizing these fluid-flow-permitting gaps, a semipermeable membrane need not be used. Depending upon the maximum size permitted for the fluid-flow-permitting gaps, it may be possible to eliminate the need for the inner barrier carrier tube. Also, in some cases a third barrier carrier tube with its own set of laterally-expandable arms may be used.
The flowable material assembly includes a delivery tube and a source of a hemostatic flowable material, typically a syringe device. The syringe device is mounted to the proximal end of the delivery tube. The delivery tube is positioned along the barrier carrier so that the distal end of the delivery tube is adjacent the distal end of the barrier carrier through the use of the delivery tube alignment device.
The elongate barrier carrier may be mounted within the delivery tube to define a flowable material path between the two. The flowable material path may be generally annular in shape.
The delivery tube may be in the form of a laterally collapsible tube. The laterally collapsible tube may be mounted to and be external of the elongate barrier carrier. This would permit the inside diameter of the introducer sheath, through which the barrier carrier and collapsible delivery tube is passed, to be of a smaller diameter than would be required if the delivery tube were not collapsible.
The distal ends of the barrier assembly and the delivery tube are inserted through the percutaneous tissue track so that the distal end of the barrier carrier extends through the access opening in the blood vessel so that the barrier is positioned within the blood vessel. Once within the blood vessel, the barrier actuator is operated to place the semipermeable barrier into the laterally expanded, deployed configuration so that the barrier can be positioned against and effectively cover the access opening in the blood vessel. The hemostatic flowable material is then directed into the percutaneous tissue track. As mentioned above, the semipermeable barrier is designed to prevent the hemostatic flowable material from entering the blood vessel. The hemostatic flowable material preferably includes a flowable gel material which swells upon contact with blood or other aqueous fluid, and a blood clotting agent which causes blood or blood components to clot, thus sealing the tissue track by creating an effective plug within the tissue track. After an appropriate period of time, which allows the blood to clot and the hemostatic flowable material to swell thus creating an effective plug in the tissue track, the barrier is placed into its laterally retracted, undeployed configuration and the barrier carrier and delivery tube are removed from the percutaneous tissue track; doing so permits the hemostatic flowable material to completely close the tissue track.
In one embodiment, the delivery tube alignment device includes a thread or other filament secured to the distal end of the barrier carrier. The thread or filament passes through the delivery tube and prevents the distal end of the delivery tube from moving distally past a chosen position along the barrier carrier. After being aligned, the proximal ends of the delivery tube and barrier carrier can be temporarily secured together using, for example, tape. The delivery tube alignment device may also comprise guides, secured to and extending laterally from one of the barrier carrier and delivery tube, which engage and slide along the other of the barrier carrier and delivery tube together, and a stop element that prevents movement of the distal end of the delivery tube past a chosen position at the distal end of the barrier carrier. Another delivery tube alignment device includes indicia or marks on the delivery tube and the barrier carrier. While using marks or indicia to properly position the distal end of the delivery tube is quite simple from a manufacturing standpoint, it relies on visual alignment of the indicia rather than mechanical alignment of the parts.
Other features and advantages will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.